Standard test sieves (Fig. 1) that conform to ASTM Specification E11 are a series of test sieves with intervals based on a fixed ratio of 4√2:1 between opening sizes (Table 1). The concept, pioneered by Peter Ritter von Rittinger of Austria in 1867, was first introduced in the United States in 1910 and has since achieved worldwide use. The number of sieves in the series and the intervals of the opening sizes have proven to be ideal for analytical separation of particulate materials to designated sizes using sieves. Since 1910, many countries have adopted national sieve standards on the basis of the same fixed ratio as the ASTM E11 Specification.